The present invention relates generally to electronic solid state and integrated circuit devices. More specifically, the present invention relates to apparatuses for dissipating heat generated by such devices.
In the electronics and computer industries, it has been well known to employ various types of electronic device packages and integrated circuit chips, such as the PENTIUM central processing unit chip (CPU) manufactured by Intel Corporation and RAM (random access memory) chips. These integrated circuit chips have a pin grid array (PGA) package and are typically installed into a socket which is soldered to a computer circuit board. These integrated circuit devices, particularly the CPU microprocessor chips, generate a great deal of heat during operation which must be removed to prevent adverse effects on operation of the system into which the device is installed. For example, a PENTIUM microprocessor, containing millions of transistors, is highly susceptible to overheating which could destroy the microprocessor device itself or other components proximal to the microprocessor.
In addition to the microprocessors discussed above, there are many other types of semiconductor device packages which are commonly used in computer equipment, for example. For example, resistors and thermistors generate large volumes of heat during normal operation and are also subject to failure if not cooled properly.
Also, the solid state devices are commonly being installed onto a circuit board which is, in turn, installed into a motherboard or other similar primary circuit board. For example, microprocessors, such as the Pentium II and the Celeron from Intel, are xe2x80x9cprocessor cardsxe2x80x9d which are installed into a motherboard of a computer in similar fashion to the way a modem is installed into a motherboard. On a given processor card is typically the processor semiconductor device package itself along with any other chips or semiconductor devices that are necessary for the operation of the card, such cache chips, or the like. The processor package may be installed into the processor card via a pin grid, ball grid, land grid array and with a socket such as a ZIF or ball grid socket.
In similar fashion to the earlier semiconductor devices discussed above, many different types of electronic devices suffer from overheating. For example, any electronic device package may have a threat of overheating. However, there are many types of electronic devices that need cooling; however, the devices are too small to adequately support and receive the typical metallic heat sink. These prior metallic heat sinks are commonly glued directly to the electronic device with a thermally conductive adhesive, or plant to the electronic device package with a mechanical structure, such as a spring clip. Further, gap pads are often required to even out the interface surface to achieve satisfactory thermal conductivity. In view of the foregoing issues related to these types of electronic components, providing heat dissipation in the form of heat sinks, and the like, are difficult and cost prohibitive.
The foregoing heat sink assemblies of the prior art suffer from the disadvantages of having multiple components and the high cost associated therewith. These multiple component heat sink assemblies typically include expensive machined or extruded heat conductive metal, such as aluminum. Other parts, such as springs or addition clips require separate machining steps and/or molds for production. Therefore, these assemblies and methods are completely inappropriate for most electronic devices.
In view the foregoing, there is a demand for a heat sink assembly that obviates the need for thermal adhesives, interface pads, mechanical connection devices as well as the need for expensive machined heat sinks. There is also a demand for a heat sink assembly that can be easily provided onto an electronic device for cooling either when the electronic device is already installed on its circuit board, on a reel fed strip of devices for installation by automatic machinery or still loose as an individual component. There is also a demand for a heat sink assembly that can provide a superior interface between the electronic device to be cooled and the heat dissipating material itself. There is a demand for a heat sink assembly that can be installed without special tools and without the need for adhesives or interface materials. There is also a demand for such a heat sink assembly to be easily removable, if desired.
The present invention preserves the advantages of prior art heat sink assemblies for integrated circuit devices, such as microprocessors. In addition, it provides new advantages not found in currently available assemblies and overcomes many disadvantages of such currently available assemblies.
The invention is generally directed to the novel and unique net-shaped formed heat sink assembly and method of manufacturing a heat sink assembly with particular application in cooling microprocessor integrated circuit devices, such as an electronic device package. The heat sink assembly and method of the present invention enables the cost-effective cooling of electronic devices while realizing superior thermal conductivity.
In accordance with the present invention, the heat sink assembly has an outer surface that includes a main body with an object receiving seat. A pair of flexible securing tabs are connected to the free edge of the open end of the main body which emanate into the open end of the main body. A heat dissipation members emanate from the outer surface of the main body to assist in dissipating the heat received by the main body from the heat generating object. The main body, the pair of flexible securing tabs and heat dissipating members are integrally formed with one another of a thermally conductive elastomeric material. An object to be cooled is inserted into the object receiving seat of the main body and retained in the seat and in communication with the inner surfaces of the main body by the pair of flexible securing tabs.
In the method of manufacture of the present invention, a main body of thermally conductive elastomeric material with an object receiving seat is provided having an inner surface and an open end with a free edge. A number of heat dissipation members are provided on the outer surface of the main body which are integrally connected to the main body. At least one flexible securing tab, preferably a pair, of thermally conductive elastomeric material is provided at the free edge of the main body and emanating into the open end of the main body. The object to be cooled is inserted into the seat of main body while the flexible securing tabs are partially bent to permit the object to be cooled to pass thereby. Once the object is fully residing in the seat and clear of the securing tabs, the tabs flex back into place to partially block the open end the seat to prevent unwanted removal of the object from the seat. Thus, the outer heat generating surface of the object to be cooled is placed into thermal communication with the inner surface of the object receiving seat to provide an effective heat sink assembly for cooling the heat generating object to ensure proper operation thereof.
It is therefore an object of the present invention to provide a heat sink assembly that is net-shaped formed with flexible material to installation onto a heat generating object, such as an electronic device.
It is an object of the present invention to provide a complete heat sink assembly that encompasses a heat generating electronic device without the need for thermally conductive adhesives.
It is a further object of the present invention to provide a complete heat sink assembly that does not require gap pads, interface materials or other mechanical structures for retaining the heat sink assembly in communication with the heat generating electronic device.
Another object of the present invention is to provide a heat sink assembly that can be installed on a series of reel-fed electronic devices for later automatic installation into a circuit board or onto the electronic device already installed on its corresponding circuit board.
It is a further object of the present invention to provide a heat sink assembly that can be easily attached to a heat generating electronic device without disturbing the device itself while, simultaneously, providing superior heat dissipation therefrom.
It is another object to provide a heat sink assembly that can be easily removed from the object to be cooled.